class ActiveSupport::TimeZone

The TimeZone class serves as a wrapper around TZInfo::Timezone instances. It allows us to do the following:

If you set config.time_zone in the Rails Application, you can access this TimeZone object via Time.zone:

# application.rb:
class Application < Rails::Application
  config.time_zone = 'Eastern Time (US & Canada)'
end

Time.zone      # => #<ActiveSupport::TimeZone:0x514834...>
Time.zone.name # => "Eastern Time (US & Canada)"
Time.zone.now  # => Sun, 18 May 2008 14:30:44 EDT -04:00

Constants

MAPPING

Keys are Rails TimeZone names, values are TZInfo identifiers.

UTC_OFFSET_WITHOUT_COLON
UTC_OFFSET_WITH_COLON

Attributes

name[R]
tzinfo[R]

Public Class Methods

[](arg) click to toggle source

Locate a specific time zone object. If the argument is a string, it is interpreted to mean the name of the timezone to locate. If it is a numeric value it is either the hour offset, or the second offset, of the timezone to find. (The first one with that offset will be returned.) Returns nil if no such time zone is known to the system.

# File lib/active_support/values/time_zone.rb, line 227
def [](arg)
  case arg
    when String
    begin
      @lazy_zones_map[arg] ||= create(arg)
    rescue TZInfo::InvalidTimezoneIdentifier
      nil
    end
    when Numeric, ActiveSupport::Duration
      arg *= 3600 if arg.abs <= 13
      all.find { |z| z.utc_offset == arg.to_i }
    else
      raise ArgumentError, "invalid argument to TimeZone[]: #{arg.inspect}"
  end
end
all() click to toggle source

Returns an array of all TimeZone objects. There are multiple TimeZone objects per time zone, in many cases, to make it easier for users to find their own time zone.

# File lib/active_support/values/time_zone.rb, line 218
def all
  @zones ||= zones_map.values.sort
end
country_zones(country_code) click to toggle source

A convenience method for returning a collection of TimeZone objects for time zones in the country specified by its ISO 3166-1 Alpha2 code.

# File lib/active_support/values/time_zone.rb, line 251
def country_zones(country_code)
  code = country_code.to_s.upcase
  @country_zones[code] ||=
    TZInfo::Country.get(code).zone_identifiers.map do |tz_id|
      name = MAPPING.key(tz_id)
      name && self[name]
    end.compact.sort!
end
create(name)
Alias for: new
find_tzinfo(name) click to toggle source
# File lib/active_support/values/time_zone.rb, line 202
def find_tzinfo(name)
  TZInfo::Timezone.new(MAPPING[name] || name)
end
new(name) click to toggle source

Returns a TimeZone instance with the given name, or nil if no such TimeZone instance exists. (This exists to support the use of this class with the composed_of macro.)

# File lib/active_support/values/time_zone.rb, line 211
def new(name)
  self[name]
end
Also aliased as: create
new(name, utc_offset = nil, tzinfo = nil) click to toggle source

Create a new TimeZone object with the given name and offset. The offset is the number of seconds that this time zone is offset from UTC (GMT). Seconds were chosen as the offset unit because that is the unit that Ruby uses to represent time zone offsets (see Time#utc_offset).

# File lib/active_support/values/time_zone.rb, line 277
def initialize(name, utc_offset = nil, tzinfo = nil)
  @name = name
  @utc_offset = utc_offset
  @tzinfo = tzinfo || TimeZone.find_tzinfo(name)
end
seconds_to_utc_offset(seconds, colon = true) click to toggle source

Assumes self represents an offset from UTC in seconds (as returned from Time#utc_offset) and turns this into an +HH:MM formatted string.

ActiveSupport::TimeZone.seconds_to_utc_offset(-21_600) # => "-06:00"
# File lib/active_support/values/time_zone.rb, line 194
def seconds_to_utc_offset(seconds, colon = true)
  format = colon ? UTC_OFFSET_WITH_COLON : UTC_OFFSET_WITHOUT_COLON
  sign = (seconds < 0 ? '-' : '+')
  hours = seconds.abs / 3600
  minutes = (seconds.abs % 3600) / 60
  format % [sign, hours, minutes]
end
us_zones() click to toggle source

A convenience method for returning a collection of TimeZone objects for time zones in the USA.

# File lib/active_support/values/time_zone.rb, line 245
def us_zones
  country_zones(:us)
end

Private Class Methods

zones_map() click to toggle source
# File lib/active_support/values/time_zone.rb, line 261
def zones_map
  @zones_map ||= begin
    MAPPING.each_key {|place| self[place]} # load all the zones
    @lazy_zones_map
  end
end

Public Instance Methods

<=>(zone) click to toggle source

Compare this time zone to the parameter. The two are compared first on their offsets, and then by name.

# File lib/active_support/values/time_zone.rb, line 304
def <=>(zone)
  return unless zone.respond_to? :utc_offset
  result = (utc_offset <=> zone.utc_offset)
  result = (name <=> zone.name) if result == 0
  result
end
=~(re) click to toggle source

Compare name and TZInfo identifier to a supplied regexp, returning true if a match is found.

# File lib/active_support/values/time_zone.rb, line 313
def =~(re)
  re === name || re === MAPPING[name]
end
at(secs) click to toggle source

Method for creating new ActiveSupport::TimeWithZone instance in time zone of self from number of seconds since the Unix epoch.

Time.zone = 'Hawaii'        # => "Hawaii"
Time.utc(2000).to_f         # => 946684800.0
Time.zone.at(946684800.0)   # => Fri, 31 Dec 1999 14:00:00 HST -10:00
# File lib/active_support/values/time_zone.rb, line 338
def at(secs)
  Time.at(secs).utc.in_time_zone(self)
end
formatted_offset(colon=true, alternate_utc_string = nil) click to toggle source

Returns a formatted string of the offset from UTC, or an alternative string if the time zone is already UTC.

zone = ActiveSupport::TimeZone['Central Time (US & Canada)']
zone.formatted_offset        # => "-06:00"
zone.formatted_offset(false) # => "-0600"
# File lib/active_support/values/time_zone.rb, line 298
def formatted_offset(colon=true, alternate_utc_string = nil)
  utc_offset == 0 && alternate_utc_string || self.class.seconds_to_utc_offset(utc_offset, colon)
end
local(*args) click to toggle source

Method for creating new ActiveSupport::TimeWithZone instance in time zone of self from given values.

Time.zone = 'Hawaii'                    # => "Hawaii"
Time.zone.local(2007, 2, 1, 15, 30, 45) # => Thu, 01 Feb 2007 15:30:45 HST -10:00
# File lib/active_support/values/time_zone.rb, line 327
def local(*args)
  time = Time.utc(*args)
  ActiveSupport::TimeWithZone.new(nil, self, time)
end
local_to_utc(time, dst=true) click to toggle source

Adjust the given time to the simultaneous time in UTC. Returns a Time.utc() instance.

# File lib/active_support/values/time_zone.rb, line 419
def local_to_utc(time, dst=true)
  tzinfo.local_to_utc(time, dst)
end
now() click to toggle source

Returns an ActiveSupport::TimeWithZone instance representing the current time in the time zone represented by self.

Time.zone = 'Hawaii'  # => "Hawaii"
Time.zone.now         # => Wed, 23 Jan 2008 20:24:27 HST -10:00
# File lib/active_support/values/time_zone.rb, line 391
def now
  time_now.utc.in_time_zone(self)
end
parse(str, now=now()) click to toggle source

Method for creating new ActiveSupport::TimeWithZone instance in time zone of self from parsed string.

Time.zone = 'Hawaii'                   # => "Hawaii"
Time.zone.parse('1999-12-31 14:00:00') # => Fri, 31 Dec 1999 14:00:00 HST -10:00

If upper components are missing from the string, they are supplied from #now:

Time.zone.now               # => Fri, 31 Dec 1999 14:00:00 HST -10:00
Time.zone.parse('22:30:00') # => Fri, 31 Dec 1999 22:30:00 HST -10:00

However, if the date component is not provided, but any other upper components are supplied, then the day of the month defaults to 1:

Time.zone.parse('Mar 2000') # => Wed, 01 Mar 2000 00:00:00 HST -10:00
# File lib/active_support/values/time_zone.rb, line 358
def parse(str, now=now())
  parts_to_time(Date._parse(str, false), now)
end
period_for_local(time, dst=true) click to toggle source

Available so that TimeZone instances respond like TZInfo::Timezone instances.

# File lib/active_support/values/time_zone.rb, line 431
def period_for_local(time, dst=true)
  tzinfo.period_for_local(time, dst)
end
period_for_utc(time) click to toggle source

Available so that TimeZone instances respond like TZInfo::Timezone instances.

# File lib/active_support/values/time_zone.rb, line 425
def period_for_utc(time)
  tzinfo.period_for_utc(time)
end
strptime(str, format, now=now()) click to toggle source

Parses str according to format and returns an ActiveSupport::TimeWithZone.

Assumes that str is a time in the time zone self, unless format includes an explicit time zone. (This is the same behavior as parse.) In either case, the returned TimeWithZone has the timezone of self.

Time.zone = 'Hawaii'                   # => "Hawaii"
Time.zone.strptime('1999-12-31 14:00:00', '%Y-%m-%d %H:%M:%S') # => Fri, 31 Dec 1999 14:00:00 HST -10:00

If upper components are missing from the string, they are supplied from #now:

Time.zone.now                              # => Fri, 31 Dec 1999 14:00:00 HST -10:00
Time.zone.strptime('22:30:00', '%H:%M:%S') # => Fri, 31 Dec 1999 22:30:00 HST -10:00

However, if the date component is not provided, but any other upper components are supplied, then the day of the month defaults to 1:

Time.zone.strptime('Mar 2000', '%b %Y') # => Wed, 01 Mar 2000 00:00:00 HST -10:00
# File lib/active_support/values/time_zone.rb, line 382
def strptime(str, format, now=now())
  parts_to_time(DateTime._strptime(str, format), now)
end
to_s() click to toggle source

Returns a textual representation of this time zone.

# File lib/active_support/values/time_zone.rb, line 318
def to_s
  "(GMT#{formatted_offset}) #{name}"
end
today() click to toggle source

Returns the current date in this time zone.

# File lib/active_support/values/time_zone.rb, line 396
def today
  tzinfo.now.to_date
end
tomorrow() click to toggle source

Returns the next date in this time zone.

# File lib/active_support/values/time_zone.rb, line 401
def tomorrow
  today + 1
end
utc_offset() click to toggle source

Returns the offset of this time zone from UTC in seconds.

# File lib/active_support/values/time_zone.rb, line 284
def utc_offset
  if @utc_offset
    @utc_offset
  else
    tzinfo.current_period.utc_offset if tzinfo && tzinfo.current_period
  end
end
utc_to_local(time) click to toggle source

Adjust the given time to the simultaneous time in the time zone represented by self. Returns a Time.utc() instance – if you want an ActiveSupport::TimeWithZone instance, use DateAndTime::Zones#in_time_zone instead.

# File lib/active_support/values/time_zone.rb, line 413
def utc_to_local(time)
  tzinfo.utc_to_local(time)
end
yesterday() click to toggle source

Returns the previous date in this time zone.

# File lib/active_support/values/time_zone.rb, line 406
def yesterday
  today - 1
end

Private Instance Methods

parts_to_time(parts, now) click to toggle source
# File lib/active_support/values/time_zone.rb, line 449
def parts_to_time(parts, now)
  raise ArgumentError, "invalid date" if parts.nil?
  return if parts.empty?

  time = Time.new(
    parts.fetch(:year, now.year),
    parts.fetch(:mon, now.month),
    parts.fetch(:mday, parts[:year] || parts[:mon] ? 1 : now.day),
    parts.fetch(:hour, 0),
    parts.fetch(:min, 0),
    parts.fetch(:sec, 0) + parts.fetch(:sec_fraction, 0),
    parts.fetch(:offset, 0)
  )

  if parts[:offset]
    TimeWithZone.new(time.utc, self)
  else
    TimeWithZone.new(nil, self, time)
  end
end
time_now() click to toggle source
# File lib/active_support/values/time_zone.rb, line 470
def time_now
  Time.now
end